Hereditary proximal colonic cancer

Abstract

Ten families prone to cancer of the colon (in the absence of familial polyposis coli) have been investigated. A significantly greater frequency of carcinomas of the proximal colon was evident relative to non-familial colonic cancers (65 per cent versus less than 35 per cent, P<.001). Moreover, family members with proximal colonic cancers experienced significantly enhanced survival, compared with family members with distal colonic or rectal cancers. Findings consistent with a genetic predisposition included early mean age at onset (45 years) and a high frequency (40 per cent) of multiple primary cancers in the patients studied. The results are in accord with reported findings in 11 similar kindreds from the literature, and strongly suggest the existence of a heritable variety of colonic cancer in which the proximal colon is at particularly high risk. Extraordinary early diagnostic measures, including colonoscopy, are indicated for members of such families.